1. Field of the Invention
The present invention relates to a method and device for the disposal of a high-expansion foam and/or a medium-expansion foam or the like, usable in connection with fire extinguishing, where the foam is suctioned with a fan blower, wherein the foam passes through the fan blower and is disintegrated in the fan blower, wherein the disintegrated foam is led via a separator into a collection container, and wherein the disintegrated foam is transferred from the collection container with a pump.
2. Brief Description of the Background of the Invention Including Prior Art
An air foam generating method is used in connection with fire-extinguishing foams, where water is transformed into a phase having a lower specific weight, in particular in relation to ignitable and flammable liquids. For this purpose, a foaming agent is admixed to a water stream and the foamable solution is foamed in a foam generator by drawing in of air. Foamable materials, which are employed for the formation of foam, are designated as foaming agents. These foaming agents are in part based on synthetic materials and they comprise for certain application compositions also special fluorotensides. The fluorotensides exhibit, on the one hand, an improved extinguishing effect but, on the other hand, represent difficulties in connection with waste disposal. High-expansion, medium-expansion, or low-expansion foam can be generated from a predetermined mixture of water and a corresponding foaming agent. The kinds of foam are defined according to their foaming numbers, i.e. the ratio of the volume of the unfoamed mixture relative to the volume of the generated foam. A low-expansion foam has an expansion ratio of from 4 to 20, a medium expansion foam has an expansion ratio of from 20 to 200, and a high-expansion foam has an expansion of over 200 up to 1000.
It can be recognized from this that medium-expansion foam as well as high-expansion foam result in large volumina of foam.
Fire-extinguishing foam is employed not only in case of a fire. Fire-extinguishing foam is also indispensable to generate an extinguishing foam for test purposes. Stationarily installed high-expansion foam and medium expansion foam systems require a government regulator's approval after a successful project performance involving a foam-generation test. In addition, foam carpets have to be generated in a mobile application for training purposes of fire-fighters. The taking down and removal, decomposition and disposal of large volumes of high-expansion foam or medium-expansion foam is accompanied today by substantial difficulties based on environmental protection considerations. The foaming agents, required for the generation of the foam, can in fact be biologically degraded. Nevertheless, the direct discharge of the foaming agents into the ground water or into a sewerage system or, respectively, into a water-clarifier and/or water-treatment plant, or into a sewage-treatment plant, results in a sudden change of the equilibrium present in such plant and can thus lead to an interference of the water biology and water chemistry present in such plant and, upon discharge from such plant, also in the ground water and waterways. For this purpose, statutory limiting values have been fixed various jurisdictions, which define a maximum permissible feeding of such foams per time unit into a sanitary sewer, storm sewer or other sewage system. These statutory limits cannot be guaranteed to be maintained during a waste foam disposal of test foams or in case of foams actually applied in case of a fire.
The large volumes of foam generated had to disintegrated in the past with large volumes of water. Another method comprises allowing the foam to rest and remain such that it is allowed to disintegrate and decompose by itself. However, this method requires a substantial amount of time.
It has already been proposed in the German Patent document P 3,931,311.5 and in the U.S. pending patent application, Ser. No. 07/585,244 now U.S. Pat. No. 5,127,959, to relieve and separate the foam by way of a fan blower in a rebound chamber and in a following pump from a large part of its air, such that it exhibits a foam expansion factor of less than 4. Such an apparatus is relatively expensive due substantial equipment requirements.